MY '77 had only one pump and I just replaced it with a low pressure pump and Holley fuel pressure regulator. Plugging off the existing return line was a major issue, I finally found a cap (12mm I think) that I got from Vibrant performance thru Summit Racing.

For linkage my second hand Redline set had the pair of clips that connect between the throttle shafts and they work ok, tho I had to fabricate a small bracket that bolts to one carb(both would be better) to hold the throttle cable.

On my 45's that go on the track car they also have the center connection although I'll see a fellow who has been building Datsun race engines for years with Weber's or Mikuni's and I'll ask him which method is best when I see him which might be as late as early June. The center connection method I've got is also the least expensive._________________Mike
Poco a Poco, '80 future track car
'77 924
cricketdesigns.com

Never a vapor lock problem with no return line. I had to fabricate a new throttle cable holder that bolts on to one of the carbs. It is a slotted hole similar to the original. I'll modify it this year to attach to the other carb also to make it more stable._________________Mike
Poco a Poco, '80 future track car
'77 924
cricketdesigns.com

I went to the auto parts store to find a plug for the return fuel line
I thought i was wise as I had found a 1/4 NPT femeale to female adapter and a plug for it.
While the male NPT screw into my oem fuel cable, the female adapter is not big enough to connect to my hard line and thus not working.
Thought i’d share the info to anyone looking into the weber upgrade.
_________________1979 924 NA

I ended up going to my local hydraulic shop as I wasn't sure of measurements.
Seems the thread on the 1979 924 is M14
They gave me a hollow nut with a ball bearing and this does the trick so far.
I ain't really nice looking in the engine bay so I might order that Holley 14mm to -6an converter.

The carbs are currently being rebuilt, will post picture once I get them back_________________1979 924 NA

I looked up the Vibrant Performance catalog. They have many metric to other thread pieces. I don't recall if it was a 12 or 14 size, but I got a piece from them to convert it to an AN probably -6 thread and then just a cap for that thread. They are in Ontario so you should be able to get direct. Look under the adapters in the fluid delivery section, they have all sizes._________________Mike
Poco a Poco, '80 future track car
'77 924
cricketdesigns.com

Did you guys got rid of the vaccum booster while doing the conversion?
From my understanding the only vaccum line I'll need is for the brake booster and from my reading a simple direct line from the intake to the brake booster would provide plenty vaccum.

Is there another vaccum line I am forgetting that would require me to keep the vaccum booster?_________________1979 924 NA

The vacuum line to brake booster is the only one you should have. Put caps on the distributor ports. I was worried about how the brakes were working and tested it, the vacuum did go up to about 20" which is what the booster needs. I may add a vacuum resevoir using a tank made from plastic pipe, which involves tapping the FI port plugs which are quite a tough material and hard to hold onto and small check valves in each of the input lines to see if the braking gets a better feel(I doubt it).

I marked the front pulley and set my timing at about 10BTDC and it runs pretty well. I'm at altitude(2400m,8000') and timing advance of about 1 degree per 1000' is not unusual in older cars.

I think the only way to really get the carbs right is to find one of the local race car builders who know webers and has access to a chassis dyno. The local(Denver) Datsun guru only took an hour to get a race TR4 dialed in._________________Mike
Poco a Poco, '80 future track car
'77 924
cricketdesigns.com